When your HVAC system blows air into your home, that changes the air pressure inside. The excess air needs somewhere to go, and that spot is the return vent. The return vent is usually bigger than your supply vents because it’s how the air handler sucks air into the HVAC system.

What is the difference between a vent and a return?

You can distinguish which vents are your supply vents because they are the ones you can feel conditioned air being blown out of. Return vents are also covers for the openings in your walls but the difference is that they are connected to your return ducts.

What is the purpose of return air ducts?

Return air ducts draw air out of each room through a separate air vent and convey it back to the central unit to be reheated or cooled. The entire air distribution system is a closed loop, continuously recirculating the same volume of air throughout the house.

Why does HVAC need a return?

Your AC’s return air vent is a critical component of an HVAC system and serves several purposes. Not only do return air vents maintain your home’s air pressure and filter out debris, they can also serve to save you on energy costs and expenses, which is important here in hot and humid Gainesville, Fla.

Do you need a return vent in every room?

While it is a myth that air return grilles are required in each and every room in the house, it is definitely necessary to have more than one of these grilles installed at strategic places in the house. … Likewise, you can also install these in rooms that have a high footfall or usage in the house.

How big should HVAC return be?

Large Returns A typical supply vent is 4 by 10 to 12 inches and a typical return vent is 16 by 20 inches or larger. Houses often have two or more return collecting points, each with a filter, which join before re-entering the heating unit.

What happens if there is not enough return air?

If there is not enough return air available, your HVAC system will not heat or cool properly. … If not enough air is brought back, your HVAC system will not be able to keep up with temperature demands. In some cases, two returns may be necessary to provide enough return air.

Can I block a return air vent?

because your HVAC system needs constant return air to work properly. A blocked air return vent will cause your system to lose efficiency and can cause premature failure of your HVAC system.

Should my return vents have filters?

Your AC system should have a proper fitting filter on the return side. By placing a good fitting, high quality filter on the return vent, you will remove particles from the air before they can enter the AC system. A good filter will keep your air handling unit, coils, and ducts clean.

Where do you put return air vents?

“An HVAC return air duct should be in every room except a bathroom and kitchen. They should be on interior walls across the room from the supply ducts that should be washing exterior walls with conditioned air.”

Article first time published on

What is the purpose of cold air return vents?

The return registers draw stale air into the ductwork, where it’s pulled through the filter to capture dust and debris and then delivered back to the HVAC equipment for reconditioning. However, the most important function of the cold air return registers is ensuring ample airflow through the HVAC system.

How do I know if I have enough return air?

Try this simple test when your HVAC system is running: get a piece of tissue paper and dangle it about six inches from one of the return vents. You should be able to see it being gently pulled towards the vent. Next, place it up against return vent and see if the air suction holds it in place.

Is it bad to close HVAC vents?

In cooling systems, closed vents lead to frozen coils, which causes damage to the system’s compressor. In both heating and air conditioner equipment, closing air vents causes damage to system components, which increases your costs in the form of system repairs and early replacement.

Can you have too much return air for furnace?

Can an air return be too big? No, an air return cannot be too big, except in extreme cases where a closed room is temporarily under negative air pressure. Return vents maintain air pressure, filter out debris, and are critical to the efficient operation of any HVAC system.

How many returns are needed in a house?

Having several return vents (ideally one in every room, but even two or three is better than just one) creates consistent air pressure. If you have one return vent, your home is fine. Keep the doors to each room open so air can properly circulate.

How much does it cost to install a return air duct?

Return Air Plenums CostsZip CodeBasicBestReturn Air Plenums – Material Prices$50.00 – $60.00$95.00 – $105.00Return Air Plenums – Installation Cost$100.25 – $100.35$150.00 – $200.00Return Air Plenums – Total$150.25 – $160.35$245.00 – $305.00

How do I even out the temperature in my house?

1. Clean the Air Ducts. If you have leaks in your air ducts, cool air won’t make it to every air vent, resulting in uneven cooling. …
2. Turn On the AC Fan. …
3. Adjust the Air Vents. …
4. Check the Insulation. …
5. Install a Zoned System.

Why is my room so hot compared to rest of house?

So, if one room is always warmer than the rest of your home, the return air vents in the room could be blocked or damaged. When this occurs, cool air is blocked from coming through those vents in your floor or ceiling, resulting in a less comfortable space.

Should return air ducts be high or low?

For optimal efficiency, it’s ideal to have return registers installed. To ensure efficiency during the cooling season, your home should have high registers. High return registers draw hot air that rises to the ceiling back into the system to repeat the cooling cycle.

What happens when you reduce duct size?

The key takeaway here is that air moves from a larger to a smaller duct, the velocity increases. When it moves from a smaller to a larger duct, the velocity decreases. In both cases, the flow rate — the amount of air moving through the duct, in cubic feet per minute — stays the same.

Can an HVAC duct be too big?

Too big – Oversized ducts will give the heated or cooled air they carry more time to come to room temperature before they get through the vents and into the room, so you’ll end up with less heating or cooling where you want it, and the system being overworked to meet demand.

Can Return air vents be on floor?

An air return vent is part of the HVAC system. Return vents are usually larger than heat registers and can generally be found close to the ground or in the floor in older homes or on a wall close to a ceiling in newer homes.

What does a return vent look like?

You can identify return vents by turning on the system fan and holding your hand or a piece of paper up. If the paper is pulled toward the vent or you feel a suction effect, it’s a return vent.

How do you clean air return vents?

Fill your sink or tub with a solution of dish soap and hot water. Immerse the vent cover in the soapy water and leave it to soak for about 20 minutes to loosen stubborn dust and grime. Remove the cover from the water and scrub both sides with a damp cloth.

Does Duct Cleaning improve airflow?

Ductwork cleaning does not improve air flow (and can actually help impede it), does not permanently remove mold or odors, and, depending on the type of ductwork, actually cause damage. Consult a certified HVAC specialist to determine the best solution to maintain your ductwork.

Why do I have two air returns?

Having two air return vents allows you to seasonally control which air is returning to the HVAC system. … The theory is that in the Summer cooling season, you want to be circulating warmer air back through the HVAC system to be cooled.

Can flex duct be used for return air?

Flex duct is widely used for return air in commercial air conditioning systems. Flex duct is able to withstand a certain negative pressure of return air. When installed properly, a flex duct is a reliable and convenient ductwork solution.

What is the best location for HVAC ducts?

Air Ducts Near the Ceiling Are Most Effective This makes the air circulation less effective and may cause the entire HVAC system to work harder than it needs to. Additionally, vents placed near the floor are at a greater risk of being clogged with dust or other debris.

What happens if you block cold air return?

In the heating cycle, blocked cold air returns can cause the heat exchanger inside the blower compartment to store too much heat and eventually crack. If the cracks are too large, the furnace can emit carbon monoxide into your home’s air. Such a condition normally requires a complete system replacement.

What happens if HVAC ducts are too small?

Ducts that are undersized will increase the static pressure, which will result in excessive noise as air moves through the system. It is often loud enough to be distracting, so it will not be difficult to overlook and should be addressed, as undersized ducts overwork the heating unit.

Why are certain rooms in my house colder?

If there is a cold room in your house, the problem has likely been caused by dirty vents, cracked ductwork, worn insulation or faint drafts.